RESUMO
This corrects the article DOI: 10.1103/PhysRevE.95.062801.
RESUMO
We present an efficient technique for the evaluation of the Gibbs adsorption of a liquid on a solid substrate. The behavior of a water nanodroplet on a silicon surface is simulated with molecular dynamics. An external field with varying strength is applied on the system to tune the solid-liquid interfacial contact area. A linear dependence of droplet's volume as a function of the contact area is observed. We introduce a modified Young-Laplace equation to explain the influence of the Gibbs adsorption on the nanodroplet volume contraction. Fitting of the molecular dynamics results with the analytical approach allows us to evaluate the number of atoms per unit area adsorbed on the substrate, which quantifies the Gibbs adsorption. Thus, a threshold of a droplet size is obtained, for which the impact of the adsorption is crucial. For instance, a water droplet with 5 nm radius has 3% of its molecules adsorbed on silicon substrate, while for droplets less than 1 nm this amount is more than 10%. The presented results could be beneficial for the evaluation of the adsorption impact on the physical-chemical properties of nanohybrid systems with large surface-to-volume ration.
RESUMO
We report on the size dependence of the surface tension of a free surface of an isotropic fluid. The size dependence of the surface tension is evaluated based on the Gibbs-Tolman-Koenig-Buff equation for positive and negative values of curvatures and the Tolman lengths. For all combinations of positive and negative signs of curvature and the Tolman length, we succeed to have a continuous function, avoiding the existing discontinuity at zero curvature (flat interfaces). As an example, a water droplet in the thermodynamical equilibrium with the vapor is analyzed in detail. The size dependence of the surface tension and the Tolman length are evaluated with the use of experimental data of the International Association for the Properties of Water and Steam. The evaluated Tolman length of our approach is in good agreement with molecular dynamics and experimental data.